Abstract:
Cefotaxime is a third generation cephalosporin with broad spectrum activity against both gram positive and gram negative bacteria. It is also effective against some strains of Pseudomonas aeruginosa. Its nephrotoxicity is low. This study wanted to evaluate various aspects of this drug (in vitro activity, efficacy, antibiotic level and safety) in order to use as a guide line for treatment of infectious diseases in Thailand. Patients studied were from department of pediatrics, Ramathibodi hospital and Pramongkutklao hospital in 1981-1982 who had serious infections and failed to respond to other antimicrobial agents. In vitro susceptibility testing of 28 strains the organisms isolated from the patients before, during, and after cefotaxime treatment by using disc diffusion technique revealed that 16 strains were sensitive (57.14%), 6 strains were inter- mediate sensitive (21.43%) and 5 strains were resistant(17. 86%). Minimum inhibitory concentration determination of these organisms by agar dilution technique revealed that E.coli, Klebsiella 'spp. and Enterobacter aerogenes were very sensitive to cefotaxime (MIC 0.031-0.125 μg/ml.) Enterobacter cloacae had higher MIC (0.125-64 μg/ml). Pseudomonas aeruginosa were relative resistant to cefotaxime. Peak (1 hour after injection) and trough serum concentration of cefotaxime in a dose of 100 mg/kg/day (divided into 4 doses every 6 hours) were 26.43±6.17 μg/ml and 2.82±0.65 μg /ml respectively. There was no evidence of drug accumulation after prolonged treatment. Cefotaxime concentration in the cerebrospinal fluid in the dose of 100-200 mg/kg/day ranged from 1.36 to 4.2 μg /ml. Urinary concentration of the drug was 265 times higher than serum concentration in patients with normal renal function and 7.6 times serum concentration in patients with renal impairment. Bacteriological results of 30 strains of causative organisms revealed 27 elimination (90%), 1 persistent (3.3%) and 2 indeterminate (6.7%). Clinical efficacy of cefotaxime was evaluated by system of infection. There were 29 site of infections in 7 systems; respiratory (7), urinary tract (4), septicemia (5) skin and soft tissue (3), central nervous system (3), intestinal and hepatobiliary (6), bone and joint (1). The results were complete resolution 20.7%, improvement 55.2%, failure 20.7%, and indeterminate 3.4%, This data indicated that cefataxime was an effective drug in the treatment of infection at various sites especially in urinary tract infection. The organisms could be eliminated from the urine in spite of in vitro resistant since the urinary concentration of the drug was very high. Ten out of 11 organisms isolated from patients with respiratory tract infection were eliminated. Only one strain (Pseudomonas aeruginosa) was persistent. However, 3 out of 7 patients were evaluated as clinical failure, This was due to severe underlying diseases. Adverse drug reactions were found in 8 out of 21 cases (38.1%). They were rashes, fever, condida superinfection, false positive Coombs' test and diarrhoea. There were no change in hematologic, liver and renal function after treatment with cefotaxime.